Mixed Platoon Flow Dispersion Model Based on Truncated Mixed Phase Distribution of Speed

The platoon dispersion model is used to depict the relationship of downstream flow profiles to upstream flow profiles, which could provide theoretical support for signal control and other applications. To evaluate the effect of the models, it is critical for them to accurately describe the characteristic of mixed traffic flow and possess an analytical solution. The latest research has shown that it is applicable to use truncated mixed Gaussian distribution to fit travel speed in the condition of heterogeneous traffic flow, but it is difficult for its corresponding platoon dispersion model to get an analytical solution. Here the truncated mixed phase distribution (TMPH), which has the merits of universality and analyticity, is proposed to substitute the truncated mixed Gaussian distribution. Then the authors can obtain the mixed platoon flow dispersion model based on this distribution. By analyzing the field data, the TMPH is indeed alternative to mixed Gaussian distribution and it can fully reflect the characteristics of mixed traffic flow. Furthermore, through the comparative analysis of the proposed model based on TMPH, Robertson’s model and the model based on truncated mixed Gaussian distribution, the authors found that the proposed model not only has good analyticity, but also could better reflect the platoon dispersion laws of mixed traffic flow.